PAM-4 transmission up to 160 Gb/s with surface normal electro-absorption modulators
10 August 2020
We report on the demonstration of multi-level modulation in polarization-independent surface-normal electroabsorption modulators (SNEAMs). Four-level pulse amplitude modulation (PAM-4) at a line rate of 44 Gb/s (22 Gbd) is demonstrated on a fully packaged SNEAM with 30-mu active area diameter and 14-GHz electro-optic bandwidth. High capacity PAM-4 transmission, at 112 Gb/s (56 Gbd) and 160 Gb/s (80 Gbd), is demonstrated on an unpackaged SNEAM chip, with 15-mu active area diameter and ultrawide electro-optic bandwidth (>>65 GHz). Transmission over standard single mode fiber using direct detection is investigated for link lengths up to 23 km at 44 Gb/s and 2 km for 112 and 160 Gb/s. Our results represent the highest bit rate achieved on a SNEAM using multi-level modulation.
